High temperature glass compositions have heretofore been produced, but they are subject to the shortcomings of having a short working temperature range or being too expensive to produce due to the high cost and energy requirements. There is thus an existing demand for glass compositions which can be readily and economically formed into long and small diameter glass fibers having high temperature, high strength and high modulus. This is particularly true for commercial aircraft and the trucking and automobile industries, for use in various insulation and acoustical products.
Aircraft have been destroyed and people's lives lost by fire, and crashes. Examples are an MD-11 which burned and destroyed in Canada, and an MD-80 which was destroyed by fire and crashed in Texas, USA, and many others. These crashes were blamed on insulation blankets which caught fire and burned. The blankets embodied fibers which were relatively low-temperature fibers and so melted at the high temperatures generated in such an emergency.
The glass compositions of this invention can be readily formed into long and/or short, stable glass fibers having the desired characteristics. Very little refining is required to provide freedom from impurities, thus allowing continuous and discontinuous fibers to be manufactured with relative ease, at a lower cost than has heretofore been practical.